1. Field of the Invention
The present invention relates to a roll stand with roll rings which are placed from one side or in a cantilevered manner on a pair of adjustable roll support shafts which are supported on two sides. Both roll support shafts have extension journals which project beyond the roll rings. Journal bearings can be slid onto and are fixable on the extension journals. The journal bearings have bearing housings which are connected with each other in a frictionally engaging manner for absorbing rolling forces by means of piston-cylinder units which can be actuated by a pressure medium and are movable parallel to the direction of adjustment of the roll support shafts, wherein one of the bearing housings is connected to the piston rods of the piston-cylinder unit and the other bearing housing, which supports the piston-cylinder unit, has sliding guide means for these piston rods.
2. Description of the Prior Art
Roll stands of this type, even though the roll rings are supported in a cantilevering mass, can absorb substantially greater rolling forces than roll stands which do not have the bearing housings for the journal bearings which can be slid onto and fixed on the extension journals. The pressure-actuated piston-cylinder units connected to the bearing housings make it possible to absorb a substantial portion of the rolling forces when the roll rings are supported from one side. In the past, this had only been possible when the roll or roll rings had been supported on two sides on both sides of the roll or roll ring in normal roll stands having two roll housings connected by means of transverse support members. Thus, it is made possible to use the arrangement of roll rings from one side even in those cases in which significantly greater rolling forces occur than, for example, in wire finishing blocks, without increasing the bearing sizes and, consequently, the roll diameters.
In addition, it is possible to use roll stands having especially great stiffnesses, such as, those with eccentric sleeve adjustment. Also, since such roll stands have relatively small dimensions, the roll stands can be placed more closely together in rolling direction. The resulting compact arrangement makes it easier to modernize existing rolling trains where space is limited.
However, in the practical operation of such roll stands in rolling trains, as disclosed in German Offenlegungsschrift No. 34 07 207, it has been found that, when the rolling stock section enters the roll gap, the rolling stock section forces one or both bearing houses outwardly away from the rolling gap by a distance corresponding to the bearing play between the bearing housing and the journal portion of the roll support shaft, and that, after the end of the rolling stock section has left the roll gap, the bearing housing or housings return into their original position as a result of their weight. This process leads to undesirable impacts.
In addition, due to the elasticity of the roll support shafts themselves and of the structural components of the system for applying pressure thereon, both journal portions of the roll support shafts which carry the rolls resiliently return by a certain distance toward the roll gap after the end of the rolling stock section has left the roll gap, so that the effect of the above-described impacts is further increased.
It is, therefore, the primary object of the present invention to provide a roll stand in which the above-described disadvantages are avoided and, consequently, the stiffness of the roll stand is increased.